Liquid-fuel injection means for prime movers



' Feb. 6, 1951 R, F D r 2,540,395

LIQUID-FUEL INJECTION MEANS FOR PRIME MOVERS Filed July 10, 1947 2Sheets-Sheet l Jiiiiiiiiiiiif 117/ z) era/ions Feb. 6, 1951 R. J. IFIELDEI'AL LIQUID-FUEL INJECTION MEANS 'FOR PRIME MOVERS Filed July 10, 19472 Sheets-Sheet 2 III! Patented Feb. 6, 1951 NT ome,

LIQUID-FUEL INJECTION MEANS FOR V PRIME MOVERS Richard Joseph Ifield andErnest Ansley Watson, Birmingham, England, assignors to Joseph LucasLimited, Birmingham,

England Application July 10., 1947, Serial No. "760,003 In Great BritainF elilualy 15, 1943 Section 1,..PublicLaw 690, August 8, 1946 Patentexpires February 15, 19.63

" In the specification 552,725 there is described and claimed aninvention which relates to liquid fuel injection systems for primemovers, and of the kind comprising a pump driven by the prime mover anda delivery nozzle or nozzles to which the fuel is supplied by the pump.The said invention comprisesa system having in combination with thepump, an accumulator which is charged by. the pump during the startingoperation, and a valve adapted to control the supply of liquid fuel fromthe pump and accumulator to the nozzle or nozzles and also adapted to beopened automatically when a predetermined quantity of liquid fuel hasbeen stored in the accumulator, or when a prede-' termined pressure isreached in the system. The said invention also comprises, for use in thesystem aforesaid, an accumulator having in combination a hollowcylindrical body part, a loaded piston slidable in the body part, and adischarge valve adapted to be opened when a predetermined quantityofliquid fuel has been supplied to the accumulator or when a predeterminedpressure is reached in the system.

In the development of the said invention we have devised a modificationwhich forms the subjeet of the -present specification.

In the accompanying sheets of explanatory drawings:

Figure 1 is "a sectional side elevation of an accumulator embodying themodification aforesaid.

Figures 2 and 3 are respectively a sectional side elevation and a partsectional end elevation of another form of accumulator embodying'thesaid modification.

In the example shown in Figure 1, we employ a hollow body part a havinga cylindrical bore 1) which extends from one end of the body part to apositionnear the other end, and which is closed at its outer end by aplate 0, the body part being herein termed a cylinder. Arranged in thecylinder bore b is a slidable piston d which is loaded at one side by ahelical spring e also contained in the cylinder bore, one end of thespring abutting against the piston and the other against the closureplate 0.- At its end remote from the closure plate 0 the cylinder at isformed with a transverse passage 1 having one end adapted for connectionby a pipe to a liquid-fuel supply pump. This passage communicates withthe inner end of the cylinder bore 12 through a lateral hole g.

At the other end of the passage 1 there is provided on the cylinder a achamber which is divided into two compartments 2', 1 by a flexiblediaphragm k, and this end of the said passage 0f British Patent No. a

' dic-ated by 11 through which 3 lever w, the latter (which leads to thecompartment 1) is provided with or adapted to serve as a valve seating Adischarge valve 12 adapted to co-operate with the seating m is attachedto or formed on the diaphragm is. In the compartment 7' maybe arranged aspring 0 for holding the valve non .its seating in until suificientfluid pressure is attained in the passage 7 to lift the valve off thecompartment :i may be open to atmosphere or it may be adapted forconnection to any desired low pressure part of the liquid fuel injectionsystem. The other compartment 1' communicates with a passage pleading toa discharge outlet q adapted for connection to a pipe leading to thedelivery nozzle or nozzles through which liquid fuel is supplied to theprime mover which drives the above-mentioned pump. g

Preferably we arrange for the passage p to be controlled by a two-wayvalve which may be operable by hand or automatically. Thus, in theexample shown in Figure 1, we provide a pair. of coaxial valve seatingsr, s in the passage p at opposite sides of the outlet 'q', and on theaxis of these seatings we arrange a slidable two-way valve t adapted toco-operate with either seating. The valve t is movable by a stem u whichhas a screw threaded part 0 in engagement with a of the cylinder a, andwhich is provided at its outer end with an actuating being operable byhand or automatically. When the valve 23 is in contact with the seatingr it establishes communication between the outlet q and the fluiddischarge compartment 2'. When the valve t is in contact with the otherseating s it interrupts communication between the outlet ;q and thefluid discharge compartment 2', and a reduced portion a: of the valvestem u serves to establish communication between the discharge outlet qand a drain pipe or passage (a part of which is shown and inliquid fuelin the pipe leading to the nozzle or nozzles can be drained to a sump orelsewhere. Preferably and as shown the portion y of the drain passage isformed in the wall of the cylinder a and is in communication with theportion of the cylinder bore b containing the spring e.

When the liquid fuel injection system containing the accumulator abovedescribed is at rest the piston d occupies its forward position underthe action of its ring 6. In this position the discharge valve nco-operates with its seating m to interrupt communication between thepassage 1 and the chamber 2'. Assuming now that the control valve t isin the position in which it establishes communication between thechamber 2' and the outlet q, and that the pump which supplies liquidfuel to the passage ,1 is started, the nrst enect of the pump is tocharge the cylinder bore b with liquid iuel against the action of thespring loaded piston d. When a suiflcient huid pressure is attained inthe passage j the valve 11 is moved ofi its seating m and establishescommunication between the passage 1' and the outlet q. The liquid fuelin the cylinder bore 1) is now discharged into the passage 1 under theaction of the spring loaded piston d. At the same time the pumpcontinues its discharge, and the combined discharges are such as willensure an ample supply of liquid fuel to the nozzle or nozzles. Thevalve n having been opened will remain open so long as the pump is inaction. To bring the pump to rest the control valve t is moved to itsother position in which it interrupts communication between the chamber1 and the outlet q, and allows liquid fuel in the pipe leading to thenozzle or nozzles to be drained.

The example shown in Figures 2 and 3 is distinguished from that shown inFigure l by various constructional details which will .now be described.Thus, the end of the cylinder a remote from the closure plate is formedwith three passages f, f and p. At one end the passage f communicateswith the inner end of the cylinder bore b, and the other end of thispassage is adapted for connection by a pipe to a liquid fuel pump. Thepassage i also communicates at one end with the inner end of thecylinder bore 1), the other end of this passage being provided with oradapted to serve as the seating m for the discharge valve 11.. As in thepreviously described example the discharge valve 11. is attached to orformed on a flexible diaphragm k which serves to divide a chamber on thecylinder 0: into two compartments 1', 1', and the compartment 7'contains a spring 0 for holding the valve on its seating m untilsufiicient fluid pressure is attained in the passage f to lift the valveoff its seating. The spring 0 is situated between the valve n and anabutment 2 which is adjustable by a screw 2 to vary the efiect of thespring on the valve. The passage 10 communicates at one end with thecompartment 1, and the other end of this passage is provided with adischarge outlet q,

the latter being adapted for connection by a pipe to the delivery nozzleor nozzles. Extending transversely across the passage p is a rotarytwo-way valve 23 of cylindrical form, this valve being supported by astationary ported sleeve 3 in a transverse bore 4 formed in thecorresponding end of the cylinder 0:. The valve t is formed with atransversehole 5, and with a longitudinal groove 5 ,in its outerperiphery. In one position of the valve 15 its hole 5 serves toestablish communication between the outlet q and the compartment i, andin another position of this valve its groove 6 serves to establishcommunication between the outlet and a pipe or passage as y throughwhich liquid fuel in the pipe leading to the nozzle or nozzles can bedrained to a sump 4 or elsewhere. The valve t is operable by hand orautomatically through the agency of a lever w on one end of the valve.The piston 11 contained in the cylinder bore b is loaded by a pair ofhelical springs e.

In other respects and in operation the example shown in Figures 2 and 3is essentially similar to that shown in Figure 1.

By employing a discharge valve carried by or formed on a flexiblediaphragm as above described, we are able to ensure greater reliabilityof action in some cases than when employing a piston-type valve, and theadditional two-way valve (when required) enables the system to be putout of action and the residual liquid fuel in the part of the systembetween the accumulator and the nozzle or nozzles to be drained awayconveniently.

Having thus described our invention what we claim as new and desire tosecure by Letters Patent is:

l. A liquid fuel injecting device having in combination a liquid fuelinlet, a liquid fuel dis: charge outlet, an accumulator cylinder havingone end in communication with said inlet so that said cylinder can becharged with liquid fuel through said inlet, a spring loaded pistonslidable in said cylinder, a valve seating arranged between the inletend of said cylinder and said discharge outlet, a valve co-operatingwith said seating and arranged to be opened by liquid pressure createdwhen said cylinder is charged with liquid fuel, and a flexible diaphragmby which said valve is supported and which is arranged so that when saidvalve is opened the liquid pres; sure acting on said valve also acts ona part of said diaphragm around said valve and thereby retains thelatter in its open position.

2. A liquid fuel injecting device as claimed in claim 1 and having incombination a two-way control valve of cylindrical form situated betweensaid discharge Valve and discharge outlet, a drain outlet connectible bysaid control valve to said discharge outlet, and a stationary support inwhich said control valve is rotatably mounted,- said control valve beingprovided with a tranvers'e hole which in one position of said controlvalve permits liquid fuel flow from said discharge valve v to saiddischarge outlet, and being also provided with a. longitudinalperipheral groove which in another position of said control valveestablishes communication between said discharge outlet and said drainoutlet.

RICHARD JOSEPH IFIELD. ERNEST AN SLEY WATSON.

REFERENCES CITED v i The following references are of record in th fileof this patent: 1

Lessmann May 20, 1941

